Array sensors are large-sized planar imaging devices, which may include pixel cell arrays, driving lines, signal reading lines and the like. In an array sensor, optical signals containing image information are directly projected onto pixel cells on a sensor imaging surface, and thus being converted by the pixel cells for creating an image. As the imaging process is implemented without using a lens or optical fibers to focus the light beams, no scaling occurs and an image obtained from this process can reflect the object in its original size. In such way, image quality can be improved. Besides, imaging devices using array sensors can be made thinner and lighter, so they are already widely used in various industrial fields.
For example, array sensor devices can be used for fingerprint imaging, file scanning, etc. As shown in FIG. 1, visible lights from a backside of an array sensor 11 irradiate onto an object 13 closely attached to an imaging surface of the array sensor 11. The visible lights may be reflected and refracted on an interface between the array sensor 11 and the object 13. Then the visible lights being reflected by the object 13 will be transmitted to pixel cells of the array sensor 11.
As shown in FIG. 2, each pixel cell includes a switching element 111 and a photoelectric element 112. The visible lights are converted into electric signals by the photoelectric element 112 in the pixel cells of the array sensor 11, and the electric signals are stored therein. A system controller 14 controls driving chips 151 of driving units 15 to control driving lines 113 of the array sensor 11, so as to activate the pixel cell array row by row. Furthermore, the system controller 14 controls signal reading chips 161 of signal sampling units 16 to read electric signals from the currently activated row in the pixel cell array through signal lines 114 of the array sensor 11. Thereafter, the electric signals are subjected to amplification and analog-digital conversion, and data resulting from these processing will be stored. As such, a digital gray scale image reflecting surface features of the object 13 being irradiated can be obtained.
The array sensor 11 generally has a glass substrate. Techniques such as Physical Vapor Deposition (PVD), Plasma Enhanced Chemical Vapor Deposition (PECVD), dry etch, wet etch and the like may be used to form one or more thin films on the glass substrate, thereby constituting electrical and optical elements for implementing various functions, and forming conducting lines. These thin films may include one or more conducting layers, insulating layers and protective layers.
Referring still to FIG. 2, in existing products, the driving chips 151 are bonded on a soft conductive film using a Chip On Film (COF) method or the like, which forms a COF module. Then the COF module is bonded to a corresponding position on the array sensor 11 using a Film On Glass (FOG) method. Therefore, driving lines 113 of the array sensor 11 are connected and electrically coupled to the driving chips 151. However, such bonding modes bring complex connecting paths between the system controller 14 and the driving lines 113 of the array sensor 11, which may reduce the reliability and occupy more areas.